240042821 has 2 divisors, whose sum is σ = 240042822. Its totient is φ = 240042820.

The previous prime is 240042809. The next prime is 240042841. The reversal of 240042821 is 128240042.

It is a happy number.

240042821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161010721 + 79032100 = 12689^2 + 8890^2 .

It is a cyclic number.

It is not a de Polignac number, because 240042821 - 2¹⁰ = 240041797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240042841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120021410 + 120021411.

It is an arithmetic number, because the mean of its divisors is an integer number (120021411).

Almost surely, 2^240042821 is an apocalyptic number.

It is an amenable number.

240042821 is a deficient number, since it is larger than the sum of its proper divisors (1).

240042821 is an equidigital number, since it uses as much as digits as its factorization.

240042821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 240042821 is about 15493.3153650211. The cubic root of 240042821 is about 621.4834586604.

Adding to 240042821 its reverse (128240042), we get a palindrome (368282863).

The spelling of 240042821 in words is "two hundred forty million, forty-two thousand, eight hundred twenty-one".